Bridge for an industrial control system using data manipulation techniques

A inter-network interface device usable in a highly reliable industrial control system provides an interface between a producer module transmitting redundant messages in accordance with a communication protocol and a consumer module receiving the messages in accordance with a different communication protocol. The inter-network interface device includes a first network interface receiving two messages from the producer, a microprocessor capable of converting the messages from the producer communication protocol to consumer communication protocol, and a second network interface transmitting the messages to the consumer. One of the messages is reversible altered with respect to the other message. The altered message is uninverted in the consumer module, and compared to the other message to ensure that no transmission errors have occurred.